Now-available test techniques cannot meet the requirements of short-time current tests for VSC-HVDC converter valves（MMC converter valves） and DC circuit breakers in Zhangbei project in terms of output power and energy. In order to solve this problem

we analyzed the current stress of MMC converter valve and DC circuit breaker

and put forward a test method based on supercapacitor energy storage and power conversion. In the supercapacitor energy storage method

the requirements of the test power supply capacity are reduced. The interleaving parallel modulation not only achieves high power output

but also reduces the current stress of the power module. The simulation and experiment results of the key equipment of Fengning converter station show that the test current can effectively track the change of current command and meet the test requirements of current equivalence.